1. Field of the Invention
The present invention relates to a hand portable system for performing quantitative thin-layer chromatography analysis.
2. Description of Related Art
Various analytical techniques are used to measure the type and amount of contamination from unknown chemicals in environmental, industrial, civilian, and military situations. Conventional thin-layer chromatography (TLC) analysis is routinely used in analytical laboratories worldwide for quantitative and qualitative characterization of unknowns. This technique is ideal for rapid pre-screening and identification of known and unknown chemicals. TLC allows multiple samples and standards (in mg to ng quantities) to be chromatographed simultaneously on a TLC plate in a solvent tank. Semiquantitative and qualitative assessment from all samples is then readily obtained by inspection of the plates, which may be chemically developed and then illuminated to display the separated components (appearing as spots). Further quantitative analysis may be performed using an illumination box, camera, and data acquisition equipment.
Unfortunately, conventional TLC apparatus is cumbersome, typically made of glass, and is not field-deployable or field-ruggedized for on-site analysis. Current TLC hardware is not hand portable when including all the necessary support equipment such as plates, tanks, solvent, pipettes, ruler, etc. Furthermore, the illumination and data acquisition equipment needed to fully analyze samples is oversized and extremely heavy. Thus, there is a need for a hand portable, field-ready TLC system, including data acquisition capability, that is cost-effective and efficient for analyzing multiple samples of unknown chemicals on-site in a variety of emergency and non-emergency situations.
The present invention is a hand portable, field-deployable thin-layer chromatography (TLC) system. This system contains many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit contains a solvent tank, a holder basket for TLC plates, and a variety of chambers for storing TLC tools. The small tank reservoir eliminates the need for a saturation pad, and a mere 10 mL of solvent can process over 100 samples. The holder basket accommodates a convenient number of TLC plates (e.g., six) and is designed to prevent aberrant wicking along the TLC plate edges. Tool chambers are available for storing pipettes, TLC plates, and a container of solvent. The unit has a window for monitoring the solvent level during the TLC plate processing, a swing-out foot for additional stability, and a gasket-sealed, screw-down lid for better solvent equilibration. The unit also includes a stencil that fits over the corner of any standard TLC plate for rapid, accurate marking of TLC plates.
In addition, a hand portable, battery-operated (or AC powered) unit for development, illumination, and data acquisition of the TLC plates has been designed. A TLC plate is positioned in a collapsible illumination box with a CCD camera, where the box and camera are optically aligned for optimal resolution of the CCD images of the TLC plate. An improved, hand portable development chamber for chemical development of TLC plates has also been designed that prevents solvent overflow.
This TLC unit and data acquisition system are ideal for on-site field analysis and identification of unknown chemicals, and there are worldwide applications to forensics, hazardous materials and environmental monitoring, law enforcement, and international treaty verification. Other objects and advantages of the present invention will become apparent from the following description and accompanying drawings.